Ceramic materials have been used in armour from at least the 1950's. However, a major disadvantage of ceramic materials is that they tend to be brittle, limiting their ability to withstand multiple hits. A first bullet impact can crack the ceramic, resulting in a loss of protection against a second impact.
One attempt to overcome this problem is to use separate tiles rather than a single plate, so limiting damage to a single tile [e.g. U.S. Pat. No. 8,006,605]. This approach has the problem that the joins between the tiles represent points of weakness and securely mounting the tiles to form a unitary body can be complex.
A related proposal has been to use segmented plates so that damage is limited to individual segments of the plate [e.g. GB2377006] however this too has the problem that the joins between segments represent points of weakness.
The traditional method of increasing multi hit capability is to increase the thickness of the ceramic strike face or increase the number of layers in the composite backing or both. This increases weight and bulk of a given armour system.
A proposal to limit the area of damage and to reduce weight is to use ceramic plates comprising a series of holes in one or both faces [e.g. GB2471702]. The holes allegedly delimit the crack propagation of one hit, providing better multi-hit tolerance than a plate without holes. However, the holes themselves may provide points of weakness, since the plate is thinner under the holes than in the body of the plate. Resistance to multiple hits is academic if the first hit penetrates the armour.
Conventionally, ceramic body armour comprises not just the ceramic plate but also features such as anti-spall layers, energy absorbing backings and materials to wrap the ceramic plate and other components together [e.g. US2003/0139108].
It has been proposed to use carbon fibre reinforced plastics as front and/or back supporting layers to a ceramic plate [US2009/0324966].